Brake device for sewing-machines.



1. HUNSINGER.

BRAKE DEVICE FOR SEWING MACHINES. APPLICATION FILED APR.14 1914.

1,134,855,, Patented-Apr. 6, 1915.

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THE NORRIS PETERS 60.. PHO10-LITHO.. WASHINGTON, D, C

JOHN nunsnvcnn, or PORT HURON, MICHIGAN.

BRAKE DEVICE FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented Apr. 6, 1915.

Application filed April 14, 1914. Serial No. 831,765.

To all whom it may concern:

Be it known that I, JOHN HUNsINGnn, a citizen of the United States, residing at Port Huron, in the county of St. Clair and State of Michigan, have inventednew and useful Improvements in Brake Devices for Sewing-Machines, of which the following is a specification.

This invention relates to brake devices for foot power sewing machines, and particularly to a clutch or brake device for controlling the direction of running movement of the drive belt, whereby under the normal conditions backward movement of the belt is prevented, allowing a positive feed mo-- tion to be quickly obtained.

The primary object of the invention 1s to provide a simple, reliable and efficient device for the purpose stated which will allow the belt to run freely in a driving direction, but will engage the belt and prevent it from moving in the reverse direction, thus overcoming the objections incident to the operation of starting a machine in which at the time of starting the belt is liable to run backward.

A further object of the invention is to provide a device of the stated character which may be employed in connection with machines in which the fly wheel runs either backward or forward with relation to the operator, and which may be drawn out of action when occasion requires.

The invention consists of the features of construction, combination and arrangement of parts herein fully described and claimed, reference being had to the accompanying drawing in which Figure 1 is a view showing the application of the invention to a sewing machine. Fig. 2 is a plan view of the work table, showing the device applied thereto, and illustrating in dotted lines the action in throwing the device out of operation. Fig. 3 is a vertical longitudinal section through the clutch casing and table, showing the position the dogs assume when the belt is running in the proper direction. Fig. 4 is a similar view showing the position the dogs assume when the belt starts to run backward.

Referring to the drawing, 1 designates the work table of a sewing machine of any ordinary construction, and 2 the drive belt, which moves through an opening 3 in the table, in the usual manner.- As is well tion can be known, this belt is driven from a drive wheel actuated by a crank and pitman connection with a foot treadle, and communicates motion to a pulley and fly wheel which is connected with the sewing machine mechanism. In starting any ordinary sewing machine, it frequently happens that the driving connections are in-position to run the belt backward, requiring the operator to time the transmission pulley in the proper direction to start the sewing mechanism. In many cases a preliminary backward motion of the belt takes place before the accorrected, causing delay, time and trouble in starting the machine, as well as possible breakage of the thread and other objections. In sewing delicate work, it is often found that the operator is compelled to release one hand from the goods to properly start the machine, when both hands are required to properly hold and manipulate the work, resulting in defective stitching or other objections. My invention provides a device which overcomes these objections, in that it allows the belt always to have proper running motion, while preventing it, unless desired, from turning backwardly.

The device comprises a casing 4, preferably of oblong rectangular form, and provided at its opposite ends with ears 5 and 6. The casing has an open bottom portion which is designed to face the surface of the table to which it is applied, and said casing is pivotally secured at one end of the table by a screw 7 passing through the ear 5, and its other car 6 is formed with a lateral slot 7' adapted for engagement with a headed screw 8, whereby the casing may be swung into and out of operative position with relation to the belt and when in operative position will be locked by engagement of the walls of the slot 7 with the screw 8. The top and one side of the casing are formed with a lateral slot 9, to admit of the passage of the belt :2 therethrough, as well as to admit the device to be thrown by lateral swinging movement into and out of engagement with the belt, said slot being arranged, when the device is in working position, in line with the opening 3.

Arranged within the casings are the clutch dogs 10, each pivotally mounted at its outerend on a pin 11, the relatively inner ends of said dogs being provided with beveled faces 12 and teeth or pointed clutch surfaces 13. These inner or engaging ends of the dogs are adapted to have a certain degree of tilting motion into a recess 14L formed in the surface of the table and communicating with the opening 3, so that the dogs may open to a prescribed extent when the belt is running in the proper direction to permit free running motion thereof. The motion of the dogs in the opposite direction is limited by the top wall of the casing 42- In the operation of the device it may be assumed that the belt 2 has a proper running motion in the direction of the arrow,

in which direction the pressure of the belt falls upon the beveled surface 12 of the dogs, thus holding the dogs pressed open so as to permit the belt to have free motion. If, however, the belt should move in the reverse direction it will carry with it the dogs, the engaging ends 13 of which impinge against the belt, a slight backward motion of the dogs serving to straighten them out'to an alining position, thus shortening the distance between their engaging ends and resulting in the belt being gripped or clutched so that its backward motion is stopped. Hence the belt is not permitted to run backward to any other than a very slight degree while it is permitted to run freely forward, thus overcoming the stated objections. If it should be desired at any time to permit the belt to be turned backward, this may be effected by swinging the device laterally out of operative position, thus releasing the belt. By then simply swinging the device back into operative position, it will be reset for further controlling action.

Copies of this patent may be obtained for five cents each, by addressing the The controlling or clutch device may be mounted either upon the top or the bottom of the work table according to the direction of running motion of the belt, or arranged in any other suitable position according to any peculiarities in the operation of the mechanism of the machine to which the device is to be applied.

1 claim:

In a device for controlling the drive belts of sewing machines, the combination with a work table having an opening therein, and a drive belt running through said opening, of a casing pivoted at one end to the underside of the work table and having an intermediate lateral slot to admit and release the belt, said casing being movable laterally with relation to the belt and also having a lateral slot at its free end, a fastening mem- K her on the work table adapted to be engaged by the slotted end of the casing for holding said casing in operative position, and gravity dogs within the casing having beveled surfaces and pointed end portions arranged in alinement with said opening and firstnamed lateral slot of the casing, said dogs being arranged to respectively permit running motion of the belt in a driving direction and to engage and lock the belt against the motion in the reverse direction.

In testimony whereof I aiiix my signature in presence of two witnesses.

JOHN HUNSINGER. Witnesses EARL FrrzsrMoNs, WALTER Gross.

Commissioner of Eatents,

Washington, D. G. 

